1. Field of the Invention
The present invention relates generally to medical fluid pumping devices and, more particularly, to a pump apparatus having a latch for securing a fluid delivery set in position on the pump to prevent the normal operative relationship between the set and the pump from being upset during a fluid pumping operation.
2. Discussion of the Prior Art
It is conventional to provide perenteral or enteral nutrition to certain patients who require the infusion of fluids, and to meter the delivery of such fluids to the patient by providing a peristaltic pump between a pre-filled fluid container and the patient.
Typically, the delivery system includes a set comprising the container, a drip chamber, a delivery outlet, and tubing connecting these elements together. The tubing extending between the drip chamber and the delivery outlet is provided with a small coupler by which the tubing is supported relative to the pump.
The drip chamber and the coupler are secured to the pump, with the tubing between the chamber and flange being stretched around a rotor of the pump. By supporting the fluid delivery set relative to the pump in this fashion, rotation of the rotor causes fluid to be peristaltically delivered to the outlet at a rate controlled by the speed of rotation of the rotor.
Numerous problems exist with this type of conventional construction. For example, no structure is provided in conventional devices which prevents the fluid delivery set from simply being unwrapped from the supported position relative to the pump, and removed from the device. Thus, it is possible for the tubing between the drip container and the outlet to be either inadvertently or intentionally removed from engagement with the rotor such that a continuous stream of fluid is allowed to be delivered unmetered directly to the patient's stomach, possibly resulting in catastrophic over-infusion.
One attempt at overcoming this shortcoming in conventional systems calls for the use of a magnetic field detector positioned on the device adjacent the point at which the coupler is supported, and the coupler includes a magnetic element capable of being recognized by the detector. Thus, a warning signal may be generated if the coupler is removed from its proper operative position.
However, it is still possible with this known device to inadvertently remove the fluid delivery set simply by pulling on the set so that it is lifted from the device. No structure is provided in the conventional constructions to prevent such removal of the delivery set.